//递归解法
int binary_search1(DataType *arr,int len,DataType value,int(* comp)(DataType,DataType))
{
if(len<=0)
return 0;
if(comp(value,arr[(len-1)/2]))
return binary_search1(arr,(len-1)/2,value,comp);
if(comp(arr[(len-1)/2],value))
return binary_search1(arr+(len-1)/2+1,len-1-(len-1)/2,value,comp);
return 1;
}
//递归
int binary_search1(int *p,int low ,int high,int goal)
{
while(low<=high)
{
int middle=(low+high)/2;
if(p[middle-1] == goal)
return middle;//查找到返回下标
else if(goal > p[middle])
return binary_search1(p,middle+1 ,high,goal);//右半区
else
return binary_search1(p,low,middle-1,goal);//左半区
}
return -1;//没有找到
}
int main()
{
DataType arr[10]={0,2,4,6,8,10,12,14,16,18};
printf("%d\n",binary_search(arr,10,0,less));
printf("%d\n",binary_search(arr,10,10,less));
printf("%d\n",binary_search(arr,10,16,less));
printf("%d\n",binary_search(arr,10,11,less));
printf("\n");
printf("%d\n",binary_search1(arr,10,0,less));
printf("%d\n",binary_search1(arr,10,10,less));
printf("%d\n",binary_search1(arr,10,16,less));
printf("%d\n",binary_search1(arr,10,11,less));
return 0;
}
